Heidi, the quintessentially Swiss mountain girl who lived with her grandfather in the Alps, may in fact have been German.
The original Heidi book was written by a Swiss author, Johanna Spyri, but scholars claim that she borrowed heavily from a book written 50 years earlier by a German, Adam von Kamp.
The suggestion of literary plagiarism - or at least heavy borrowing of characters, setting and plot line - in one of the classics of Swiss literature has set off an unseemly squabble between the alpine neighbours.
It has also fueled the traditional animosity among German-speaking Swiss towards what they regard as the “arrogance” of their big northern neighbours in Germany.
Peter Buettner, the researcher who has come up with the claim, has a foot in both camps - he is German but based in Zurich.
“I didn’t say Spyri copied,” the German book, said Buettner, an expert in German literature and culture. “But I’m assuming that Spyri knew the work and it helped inspire her.” He insists that he “never wanted to take Heidi away from the Swiss.”
Nevertheless he believes there are striking similarities between ‘Heidi’ and the earlier work, which was titled ‘Adelaide, the Girl from the Alps’.
Both revolve around little girls who are brought up by their grandfathers and become miserable when they are forced to leave their homes in the mountains. In the case of the orphan Heidi, her aunt first places her in the care of her grandfather but then returns and takes her to Frankfurt.
Even the titles of the books are similar - Heidi is a shortened form of Adelaide, or Adelheid in German.
Both Heidi and Adelaide are cheerful, kind little girls who dote on their grandfathers and delight in picking wild flowers in mountain meadows.
There are episodes in Heidi which closely resemble scenes in Adelaide, including one in which the girls each turn down an offer of money from their grandfathers.
The Swiss have rallied to the defence of their literary icon, saying that many 19th century writers in central Europe were preoccupied by the drift to the cities and the possible harmful effects on children.